Determining Critical Period for Weed Control of Garlic (Allium sativum) in Chemical and Organic nutrition Management

Weeds control is very important to achieve optimal yield in agricultural products. The purpose of this study was to determine the critical period for weed control (CPWC).of garlic in chemical and organic nutrition management in Ramhormoz.

A factorial experiment based on randomized complete block design (RCBD) was carried out in 2019—2020 with three replications in Khuzestan-Ramhormoz province. The first factor included nutritional management (chemical and organic) and the second factor included 12 treatments of interference and control period of weeds (0, 20, 40, 60, 80, 120 and 160 days).

Determining the critical period of garlic weed control in two chemical and organic nutrition management revealed that the beginning of the critical period in organic application will be happen later than chemical fertilizers. Also, the end of the critical period in chemical application of was predicted later than fertilizers. Also, the end of the critical period in application chemical was predicted later than organic fertilizers. The length of the critical period for weed control was higher than in chemical than chemical application compared to organic fertilizers. With 5% loss yield, the beginning, end and length duration of the critical period for weeds control in organic management were 202, 1518 and 1316 GDD and in application chemical fertilizers were estimated 210, 1638 and 1428 GDD respectively.

The results indicated that length duration critical period for weed control in organic nutrition management (120 days) will be shorter than chemical management (127 days).